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Sunday, May 22, 2016

Peilinia quadriplicata pelecypod from Texas

Another pretty cool looking oyster that I found in the Texas creek I was exploring is Peilinia quadriplicata (also called Ostrea quadriplicata). This species is very easy to ID based on the look of the shell. I only found a left valve but it has the typical splayed look to it, kind of like a duck foot. While the shell started out with a relatively smooth margin, as the animal grew older it started to have some distinct "points" with flat, straight areas of margin between them. Overall the shell is subpentagonal in shape with some obvious, widely spaced growth lines. There is also some gentle undulations on parts of the shell. The interior of the valve is smooth with a scallop shaped indentation where muscles once attached.

Left valve, top view

Ventral view

Interior view

Dorsal view

Right profile

Left profile

I found the above specimen in a creek that cuts through the Duck Creek formation but P. quadriplicata is not found in those rocks. Likely this washed downstream from a higher, younger formation such as the Denton Clay or Paw Paw formation which are Cretaceous (Albian and Cenomanian stages respectively) in age.

About Me

I'm a 40-something, life long student of Geology living in Philadelphia. My interests include Photography, Architecture and History among other things. When not cleaning my recent finds you'll find me in my backyard Hybridizing Daylilies or working in my garden. This Blog is an outlet for me to express my interest in fossils, catalog my collection and coalesce my thoughts and research into a useful medium.